Jersey number/scorebook question

[rockchalk jhawk]

BV, second half of a blowout game. Player from H (who is down by 30) checks in during a timeout. Table called me over and informed me that the player who just checked into the game wasn't listed in the scorebook. I call over my nearest partner and tell them what happened, that'd we'd have an admin T and be shooting free throws, etc. Before any signaling of the T or anything like that, I went over to the coach to explain to him that his player wasn't in the book. He instantly got a panicked look on his face and told me that the kid had gotten blood on his uni in the JV game and that they'd switched jersey's. We asked the kid what his number was supposed to be and he instantly replied 11. There was in fact an 11 in the book. They were down by 30 and coach was just wanting to get some JV kids in the game. We played on since the kid was obviously supposed to be number 11. We played on and both coaches were fine with that.

What would you/should we have done?